Vava'u is served by Lupepau'u International Airport (IATA: VAV) on the northern part of the main island, about 15 kilometres from Neiafu. Real Tonga operates daily flights from Tongatapu (roughly 1 hour); Fiji Airways has direct connections from Nadi, Fiji. The ferry from Tongatapu takes around 18–24 hours depending on the vessel and weather, and is genuinely rough in the wet season — the flight is strongly recommended unless you have a lot of time and good sea legs.
From Neiafu, the airport is a short taxi or minivan ride. Most accommodation will arrange a pick-up if contacted in advance.